Eisinga Planetariumとは 意味・読み方・使い方

The Eisinga Planetarium is an orrery, a working model of the solar system. It was built from 1774 to 1781 by Eise Eisinger in Franeker. The "face" of the model looks down from the ceiling of a room, with most of the mechanical works in the space above the ceiling. It is driven by a pendulum clock, which has 9 weights or ponds. The planets move around the model in real time, automatically. (A slight "re-setting" must be done by hand... provided for by Eise... every four years to compensate for the February 29th of a leap year.)